Synaptic Transmission

• Synaptic transmission


  1. Neurotransmitters are released by the presynaptic neuron

  2. Neurotransmitters bind to receptors on the postsynaptic neuron

  3. This changes the electrical charge inside the postsynaptic neuron

  4. If the charge passes a threshold, a new action potential forms and the message is passed on

  5. Neurotransmitters detach from receptors and are reuptaken by the presynaptic neuron
• Excitation


  Excitatory neurotransmitters increase the likelihood of a new action potential forming in the postsynaptic cell, the electrical charge inside becomes more positive and likely to fire (depolarization)
• Inhibition


  Inhibitory neurotransmitters decrease the likelihood of a new action potential forming in the postsynaptic cell, the electrical charge inside becomes more negative and less likely to fire (hyperpolarization)
• Summation


  The combined effect of all inhibitory and excitatory influences, resulting in a new action potential forming or not
• Information can only be passed between the pre- and post-synaptic neurons in one direction, due to the structure of the synapse